Hi David: In the year 2008, it seems most people do NOT know what the BCC: field is in their e-mail programs, or when to use it.

In the past week, I’ve received e-mail from people that I do not even know, where my address was in a list of 493 people, all visibly placed in the CC: field. This drives me into a homicidal rage.

I would not mind if it was the infrequent occurrence. It is not. It is common — mind-numbingly so.

When I write the sender to both ream them and educate them, the response is ALWAYS the same. It usually goes something like, “Oh, that’s what BCC means — blind carbon copy!”

Please, do your bit for humanity. Help put a stop to this rampant, idiotic misuse of e-mail protocols and netiquette. I’m begging you.

Just about ready to drink Drano, Frank

Back away from the drain cleaner, sir. There’s no need for that.

Here’s the explanation you seek.

A blind carbon copy is a secret copy. This feature lets you send a copy of a message to somebody secretly, without any of the other recipients’ knowing that you did so.

You can use the “BCC:” field to quietly signal a third party that a message has been sent. For example, if you send your co-worker a message that says, “Chris, it bothers me that you’ve been cheating the customers,” you could BCC your supervisors to clue them in without getting into trouble with Chris.

The BCC box is useful in other ways, too. Clueless people often send e-mail messages (jokes, for example) to a long list of friends. You, the recipient, have to scroll through a very long list of names the sender placed in the “To:” or “CC:” field.

But if the sender used the “BCC:” field to hold all the recipients’ e-mail addresses, you, the recipient, won’t see any names but the sender’s, or maybe your own, at the top of the e-mail. (Spammers have also learned this trick, which is why it usually looks as if you’re the only recipient of junk messages when there are actually millions of other people who received the same message.)